package com.washmadam.service.common.utils;

import java.security.MessageDigest;


public class MD5Util {

    private static String key = "87228c3b56564585f";


    private static String byteArrayToHexString(byte b[]) {
        StringBuffer resultSb = new StringBuffer();
        for (int i = 0; i < b.length; i++) {

            resultSb.append(byteToHexString(b[i]));
        }

        return resultSb.toString();
    }

    private static String byteToHexString(byte b) {
        int n = b;
        if (n < 0) {
            n += 256;
        }
        int d1 = n / 16;
        int d2 = n % 16;
        return hexDigits[d1] + hexDigits[d2];
    }

    public static String MD5Encode(String origin, String charsetname) {
        String resultString = null;
        try {
            resultString = new String(origin);
            MessageDigest md = MessageDigest.getInstance("MD5");
            if (charsetname == null || "".equals(charsetname)) {

                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes()));
            } else {

                resultString = byteArrayToHexString(md.digest(resultString
                        .getBytes(charsetname)));
            }
        } catch (Exception exception) {
        }
        return resultString;
    }

    private static final String hexDigits[] = {"0", "1", "2", "3", "4", "5",
            "6", "7", "8", "9", "a", "b", "c", "d", "e", "f"};

    public static final String md5Digest(String src) throws Exception {
        if (src == null) {
            return "";
        } else {
            src = src + key;
            char[] hexDigits = new char[]{'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f'};
            MessageDigest alg = MessageDigest.getInstance("MD5");
            byte[] tmp = alg.digest((src).getBytes("UTF-8"));
            char[] str = new char[32];
            int k = 0;

            for (int i = 0; i < 16; ++i) {
                byte byte0 = tmp[i];
                str[k++] = hexDigits[byte0 >>> 4 & 15];
                str[k++] = hexDigits[byte0 & 15];
            }

            return new String(str);
        }
    }

}
